Variable speed impact machine



Feb. 6, 1940. 2,188,898

R. K. HASKELL El AL VARIABLE SPEED IMPACT MACHINE Filed July 29, 1938 2 Sheets-Sheet I Inventor-5 Robert Kfiaskell Harald B -Ma'rm Feb. 6, 1940. R, HASKELL r AL 2,188,898

VARIABLE SPEED IMPACT MACHINE Filed July 29, 1938 2 Sheets-Sheet 2 Inventors Ruhert K-Ha5kel1 Harald llMan n E3 Am Attorney Patented Feb. 6, 1940 UNITED" STATES.

FFICE VARIABLE SPEED IMrAc'r MACHINE Robert K. Haskell and Harold C. Mann,

1 Watertown, Mass.

Application July 29, 1938, Serial No. 221,967

' 5 Claims.

governmental purposes, without the payment to us of any royalty thereon.

The subject of this invention is a variable speed impact machine for testing material to the breaking point by impact.

The main object of the invention is the provision of a device in which the impact element is moving at a predetermined speedat impact and one in which the. force be indicated. v

' The invention resides broadly in the instant of or" impact will the provision mounted av centrifugally actuated mally locked in retracted position striker, norby alock bar extending diametrically between the disks and rotated by suitable gearing to locked position, with releasable means for and unlocked actuating the gearing at desired times, and a pendulum for mounting a test specimen in the path of the striker or hammer when extended.

A practical embodiment of the invention is shown by way of illustration in the accompanying drawings, wherein, g Fig. 1 is a view in side elevation parts broken away;

Fig. 2 is a view in end elevation section.

of the device, 8

with parts in Fig. 3 is an enlarged view inside elevation of .the rotatable disks parts broken away and parts v Fig. 6.

Referring to the drawings by numerals of reference: c There is provided a suitable base central shaft;

sectional viewon the line 6-4 5 of Fig. 7 isa sectional viewon the line 1-4 of upon which the spaceduprights 2 are mounted the upper por- 'tions of which are adaptedto receive. the hollow shaft 3 whichisjournaled therein,

lhe shaft 3 is formed centrally with an flange 4 to each side of which is an annular enlarged portion or hub 5 adapted to receive the discs 5 which are keyed to the respective hubs as at l and are I spaced apart by the flange 4.

uprights 2 and surrounding the shaft 3 receive the bearings 8 of a pendulum member which consists of, sides 9 depending from the bearings and having their lower ends connected by a cross plate H2. A .plate I I mounted as by bolts I 2 on the cross plate lllis formed with a slot for the reception of a specimen holder 13 which may be secured in place by the bolt Hi and which is conveniently provided with a handle it for removal of the, holder when the bolt is unscrewed. There is shown mounted in the holder a shear type specimen it with the usual tup, I l, but it is to be understood that other typespecimens may be substituted therefore.

' Mount-ed for osoillationonbne of the studs 8 and adjacent to one side plate of the pendulum is a pointer it which is adapted to be contacted by a finger it carried by the pendulum so'that the pointer will be carried bythe pendulum on its initial upward swing under the force of a blow on the tup H and will remain in such position through frictional contact until moved manually to its normal position.

A scale may be carried by an upright 2 against which the pointer 58 is read to indicate the force of the blow delivered to the tap carried by the test specimen.

Insertedin'the hollow shaft 3 (Fig. 4) to slide axially thereof is a shaft 2! provided with a key 22 to fit in a keyway 23 of the shaft 3. Secured 'in the outer end of the shaft 25, as by a pin 2a, is a plug having a threaded portion 25 and a head 26; Mounted on the threaded portion 25, andm I normally in engagement with the head 26 and'the end of the shaft 3, is a cam nut 21. A removable stop 28 is inserted in an aperture formed in the shaft 3 and extends into the keyway 23 to limit the outward throw of the shaft 2|.

Encircling the shaft 3 with its outer jfaceflu'sh with the end'of said shaft is a ring 29 formedwith a flat 30 (Fig. 3) in its periphery.- This ring is held in place on the shaft as by a set screw 3! the pointed end of which seats in an annular groove 32 formed in the shaft 3..

Attached to a standard 2 in any suitable man- .ner is a plate 33 (Fig.3) upon which is pivotally mounted a lever 34 pressed by a plunger 35130- ward the ring 25. The plunger 35 is mounted in a casing 35 carried by the plate 33 and is urged by a spring 3'! toward the lever 3 A suitable latch is provided for v holding the lever 34 against'the action of the plunger 35, the same, as herein shown consisting of a plunger 38 mounted in a housing 39 carried by the plate 33 plunger 38 is provided with a knob M and which may be grasped to withdraw the plunger from its position beneath the lever 34.

The lever 33 includes a bell crank arm or finger 42 adapted to normally engage: a dog d3 pivoted to an extension 44 of a housing 55 in which there is a plunger 46, the inner end of which is forced against the dog by a spring 41. The dog 43, when released by the detaining finger 2-2 through swing of the lever 34 is adapted to engage the lip 48 on the cam nut 21 to hold the same against rotation with respect to the shaft 2! and to thereby cause the shaft, through the action of the threads, to be drawn to the left as viewed in Figs. 2 and 4. A knob 59 may be provided on the outer end of the plunger 48 for convenience in setting the device.

The shaft 2] has formed on its inner end' a rack 50 meshingwith a pinion 5! on a rod 52 which extends diametrically between the discs 6, passing through the hollow shaft 3 and mounted in the brackets 53 carried by the discs. The opposite ends of the shaft 52 are provided with means for releasably holding a striker or hammer 54 and a somewhat similar counterbalance 55 each of which is pivotally carried by and between the discs adjacent the periphery thereof. The holding connections are similar and are illustrated in detail in Figs. 6 and 7 in which the hammer, for example, is provided with a cylindrical opening 56 having opposite slots 5'! to provide clearance. Interrupted teeth 53-58 formed in opposite walls of the opening 55 are adapted to be engaged by interrupted teeth 59-59 on opposite sides'of the rod 52. When the shaft is turned degrees the teeth 59 are disposed in the slots 51.

The striker or hammer 54 may be of any suitable form', the one herein shown being fashioned 65-455 which lie in recesses 66-65 formed in, the

inner faces of the discs 6 when in rotated position, do' not extend beyond the periphery of the discs. 1 In preparing the machine'for operation the parts are in the positions shown in full lines in Figs. 3 and l, the hammer and the counterweight being held in retracted position, the dog i3 held out of engagement with the lip 48 on the nut 27, and the shaft 2! moved to the right with the head 26 in engagement with the nut.

In operation the discs 8 and shaft 3 are rotated by any suitable power until a desired speed is attained whereupon the knob 58 is grasped.

and the plunger 38 withdrawn to release the lever 34. The lever 34 is now free to be moved into contact with the periphery of the ring 29 where it drops onto the fiat 30 and the finger 42 is moved to further retract and then release the dog 43. The dog 33 is now moved by the plunger 53 into engagement'with the nut 21 where it engages the lip 48 of the nut 21 and holds the nut stationary.

The shaft 2| which is being rotated by virtue of its connection with the shaft 3 through key 22 is unthreaded from the nut and displaced to the left until the key 22 engages the stop 28. During this displacement the rack 50 imparts. a

quarter turn to rod 52 to move the teeth 59 clear of the teeth 58 and release the hammer and.

counterweight. ence of centrifugal force acting on the heavier extensions (53 is rotated to the extended position shown in dotted lines in Fig. 3 where the striking elements'63 are supported by the stop: surfaces 542) and impact the tup l1.

'Wh'en the hammer strikes the tup which is.

carried bythe pendulum the latter is oscillated and the amount of oscillation transmitted by the finger 19 to thepointer l8 which is read against The hammer under the influ-- the scale 20 and thereby indicates the force of] a hammer disposed between the discs and pivoted therein, acounterbalance pivotally carried by the discs oppositely to the hammer, a rod passing through the hollow shaft diametrically of tinediscs, interrupted teeth on the opposite v ends of the rod,-interrupted teethon the hammer andon the counterbalance and engageable. by the teeth on the rod to hold the hammer-and,

counterbalance in retracted position within the periphery of the discs, means for rotating the rod to disengage its teeth from the hammer and s I counterbalance and release these members for rotation under the influence of centrifugal force upon rotation of the disc, and a pendulum adapted for mounting a test specimen in the path of i the released hammer. Y

l 2. A variable speed impact machine embody ing a support, a rotatable element journaled in the support, a. normally retracted hammer car-J ried by the element, a rod for holding the hammer in retracted position against the influence of centrifugal force tending to extend it, a shaft. movable axially of the rotatable element, and

rotatable therewith, gearing between the shaftiq.

and rod to move the rod into locking and un 1 locking relation to the hammer, said element I having a flat, a nut threaded on the'shaft, a'. dog

carried by the support and movable into engage-' ment with the nut to hold the nut againstgro tation, a lever engageable with the shaft and.

movable onto the fiat of the element to release the dog, a latch for holding the lever off of the fiat, and a pendulum'edaptedfo'r mounting a;

test specimen in the path of the hammer, when extended. I

3. A variable speed impact machineembody ing a support, a rotatable element journaled' in} the support, a normally retracted hammer car ried by the element, a rod for holding the hammer in retracted position against the infiuence ofcentrifugal, force tending to extend it, ashaftmovable axially of the rotatable element an'dlrotatable therewith, gearing betweenthe shaft and rod to move the rod intolocking and unlocking relation to the hammer, mechanism adjacent the shaft and cooperating when manually released with means on'the shaft toautomatically dis a pendulum adapted for mounting a testspeciing a support, a rotatable'element journaled in .70 place the shaft axially to rotate the rodfand the support, a normally retracted hammer car-' ried by the element, a rod for holding the ham!- mer in retracted positionagainst the influence of centrifugal force tendingto extend it, a-shaft I movable axially of the rotatable element, and rotatable therewith, a connection between the shaft and rod whereby axial displacement of the shaft moves the rod to release the hammer, means for axially displacing the shaft, manually operable means for controlling actuation of said preceding rneans, and a'pendulum adapted for mounting a test specimen in the path of the hamm'erwhen extended. 7

5. A variable speed impact machine embodytrifugal force tending to extend it, means within the hollow shaft for actuating said member to release the hammer, and a pendulum adapted for mounting a'test specimen in the path of the 10 released hammer.

l ROBERT K. 'HASKELL;

HAROLD C. MANN. 

